The invention described herein relates generally to rotary devices and more specifically to rotary engines capable of employing either external or internal combustion to provide motive force.
A major disadvantage of the standard piston-type engine is its difficulty in operation at high rotational speeds. This is due to the inherent inefficiencies and vibration associated with transforming reciprocal motion into rotational motion.
Some problems of the piston engine have been minimized by present rotary engines. Their designs, however, have engendered problems of their own. For example, the Wankel engine and its variations, utilizing rotating lobes within an inner chamber to achieve intake, compression, expansion and exhaust require some type of tip or vane between the lobes and the inner chamber wall to define the work chambers within the engine. These vanes or tips are designed to slide either along the inner chamber wall or against the lobes. Such constant surface movement wears the vanes or tips causing the loss of chamber integrity, thereby reducing engine efficiency.
When an engine operated from an external heat source requires a membrane to separate the working medium from the heating or cooling medium, another disadvantage becomes evident. Heat transfer can be accomplished only by conducting through the membrane.
Furthermore, with the conservation of energy rapidly increasing in importance, an engine is undesirable if it cannot be easily adapted to a variety of energy sources, for example coal, geothermal heat and gasoline.
Therefore, there is a definite need in the art for an engine which is easily adaptable to a variety of modes of operation, which is capable of high rotational speeds and which is not subject to poor chamber definition. Furthermore, there is a definite need for an engine operable from an external heat source which does not require a membrane to separate the working medium from that used to cool or heat.
It is therefore an object of the present invention to provide an engine of fully rotational design.
It is a further object of the present invention to provide an engine adaptable to internal combustion as well as being operable using an external heat source.
It is another object of the present invention to provide an engine minimizing seal wear and poor chamber definition.
It is an additional object of the present invention to provide an engine capable of operation from an external heat source which does not require separation of the working medium from the heating or cooling medium.